Nine seasons in and Supernatural shows no signs of slowing down. The family business, "hunting things," is a-boomin', with last week's premiere attracting the series' best ratings in three years. Even better, the storylines and the relationship between Dean (Jensen Ackles) and Sam (Jared Padalecki) still feel fresh, proving the show is as resilient as Dean's beloved Impala.

We chatted with showrunner Jeremy Carver about the impressive ratings boost and why fans are still so passionate about the series nine years in. Plus, he dropped scoop on what viewers can expect from Sam and Dean's relationship after Dean's polarizing decision in the premiere, as well as Castiel's (Misha Collins) new role as a mere mortal...

Though its in its ninth season, Supernatural's premiere garnered the series' best ratings in three years, a feat Carver calls "bonkers." So what's his theory behind the ratings boost?

"It's really a testament to the incredible fans that we have, and I think, I mean, my only guess is that their enthusiasm is starting to have an effect on other folks, because it appears new people have been checking it out," he explains. "I think they have such a strong presence online, whether it be Tumblr, or the various boards, or even on Twitter, that I think other folks are catching that level of excitement and it's really, really exciting."

Of course, there's always the appeal of the Winchester brothers, right? Especially when one (this season: Dean) is trying to save the other (Sam's turn!), a storyline the series has utlilized several times now. "It's not even necessarily the brothers saving each other. The show works best when it's the brothers facing some conflict together," Carver says. "It's not just facing a monster. If it was just how do we kill this monster of the week, the show would not be on the air, to be perfectly frank. It's a show that has infused this brotherly relationship and extending it to the supporting characters, so it's this familial structure that keeps people coming back."

Of course, Sam and Dean's relationship is once again going to be tested after Dean convinced Sam not to close the gates of hell and then decided to let an angel, Ezekiel (Tahmoh Penikett), take over Sam's body, unbeknownst to his little bro, in the season premiere.

"Dean, for the first time in a long time, has made two enormous decisions that are really going be driving the mythology in ways expected and unexpected, and that's a really heavy burden for him to be shouldering," Carver explains. "One particularly more difficult because people he might be able to talk to about this, he can't—in particular, Sam, because Sam can't know. So it's like, what do you do when you find yourself perhaps that the only person, or one of the few people you can talk to about the angel in your brother Sam is the angel in your brother Sam?"

Carver promises that the situation will lead to "so some humorous situations, some heartbreaking situations, some irksome situations." Translation: Dean will be feeling all the feelings this season.

Unfortunately for fans dying to know when fan favorite former angel Castiel will be reunited with the brothers, Carver is keeping that information super-secret, only saying, "We're going to see a reunion soon." To be fair, Cas is pretty busy dealing with the whole being human thing while being hunted by a crapload of pissed off angels.

"He is facing this really crucial decision here, where he can adjust and accept what he is now, which is human, in the face of what he used to be. It's a really tricky thing for him, because he's gotta eat, he's gotta sleep, he's gotta wash, he's gotta do all these things. He can't ignore what are the most basic of needs for him now, whereas there's this greater thing going on that pretty much no one knows about," he previews. "I think we're gonna find a Cas who's really put through his paces as he's trying to adjust to being human, while also trying to figure out where he stands now, in this greater angel landscape. Of course all the time trying not to be hunted down by the angels who want to kill him."

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